Reply to 'Marital status and risk of cardiovascular diseases: a systematic review and meta-analysis

We would like to congratulate Wong et al1 for their comprehensive work on the important issue of the impact of marital status on cardiovascular disease, showing the protective effect of marriage and detrimental effect of divorce on cardiac health. The main strength of this study is the 2 million participants despite a robust study design that included only prospective studies.

Naturally, the ability for such a well-designed meta-analysis to achieve large participant numbers is dependent on the availability of an array of well-designed studies. The individual prospective studies included in this meta-analysis have an advantage of fewer potential sources of bias and confounding when compared with retrospective studies, but the majority of the 34 studies included required participant follow-up implying significant cost and workload. Thus, there is enormous potential in using routinely collected and readily available real-world data.